Joseph bothchild



NITED STATES QATENT i rrcn.

JOSEPH ROTHCHILD, OF FRANKFORI, KENTUCKY, ASSIGNOR OF ONEHALF TO HIBAM BERRY, OF SAME PLACE.

SAFETY DEVICE FOR ENGINES.-

EPECIPICATION forming part of Letters Patent No. 35%,938, dated December 28, 1885.

Application filed May 8, 1856. Serial "No. 201.6l8. (N model.)

To all whom it may concern.-

Be it known that I, JosEPH RoTHoHrLD, a citizen of the United States, residing at Frankfort, in the county of Franklin and State of Kentucky, have invented certain new and useful Improvements in Safety Devices for Engines, of which the following is a specification. My invention relates to safety devices for fluid-pressure engines; and it has for its obro ject to provide means whereby such engines may be automatically controlled when operat ing abnormally and rendered normally operative or entirely inoperative.

It is well known that fluid-pressure engines, 1 5 and more especially pumping-engines, are liable to race or run away, and this, too, even when provided with the ordinary governing devices. For instance, supposingapumpis at Work up to its full capacity, and for some reason the supply of liquid to be lifted gives out, the fiuid-pressure actuating the engine or pump remains constant, and the work to be performed suddenly grows less or absolutely disappears. Under these circumstances the engine or pump immediately commences to run away or race, and greatdamage may be done unless some means is provided to reduce the pressure to a point of safety.

It is the object of my invention to provide such means in a simple and cheap form, and

one that may be applied to all kinds of fluidpressure engines without interfering with the operation of the other parts of such engine; and to this end my invention consists in a 5 safety device constructed and arranged substantially as hereinafter described.

Referring to the accompanying drawings, forming part of the specification, Figure 1 is a side elevation of one form of pump, showing my improvement applied thereto. Fig. 2

is an end view thereof. Fig. 3 is a detail showing one form of pawl-and-ratchet movement.

Inthe drawings, A represents any fluid-pressure engine, and B the pipe or conduit connect- 5 ing said engine with any fluid-pressure generator, and O is the valve controlling the fluid in said pipe in the ordinary way, and it may be of any usual construction and operated in any manner, as by a hand-wheel.

the safety device to this ordinary valve or to a special valve, and connect the device to some I apply of the operating parts of the engine, so that it will be controlled thereby, and will in turn control the fluid-pressure operating the engine. Various mechanical means may be used for this purpose, as is evident, and I have shown one simple form of such means in the drawings, and I will now proceed to describe the same in detail.

Rigidly connected with the valve stem is a ratchet-wheel, D, and loosely mounted upon said stem is a pendulum or swinging rod, E, carrying at its upper end a pawl, F, engaging with the ratchet-wheel, and the lower end is connected to some operative part of the engine and controlled thereby.

The particular engine illustrated in the drawings is a pump of well-known construction, in which the reciprocations of the piston and piston-rod operate the valve by means of some attachment to said piston-rod engaging with the valve rod or stem at or near the end of its stroke, and as the construction and operation of such pumps or engines are well k nown they need not be more fully described 7 5 herein. Various means of connecting I the pendulous rod E with said engine may be employed, that shown in the drawings being simple and effective and well adapted to the particular kind of engine illustrated, and it consists of a rod or bar, G, having oneend connected to the pendulum or swinging rod E, and the other supported upon the engine, as by an arm, G. Upon this connecting-rod are placed adjustable stops or collars g, and operating in connection with the rod and stops orcollars thereon is an arm, H, connected with the piston or valve rod of the engine, which arm strikes against one of the stops or collars at each reciprocation of the piston or 0 valve rod, moving the rod G'and its connected pendulum or swinging bar.

In order that the connectingrod may not move too far or too easily, some friction device maybe used, as at S,consisting of aspri'ng 5 'bearing upon said rod, and held in position consisting of springs j and adjustable stops or collars j.

In order that the pendulum or swinging rod may have the desired inertia and momentum, it is provided with an adjustable weight, K. The pawl may also be provided with a suitable thumb-piece, f, so that it may be easily raised when it is desired to move the valve 0 independently of the safety devices. 1

The operation of the device will be understood from the drawings, and is the same in principle whatever the specific construction to ofthedevice. Supposingforinstance,themain valve in starting the engine or pump is opened too far, thus allowing more pressure from the fluid than is needed to normally run the engine, the arm H, connected to the piston or valve rod, will, before the engine attains its full speed under the pressure, just impinge upon the steps or collars g with slight striking force, and, owing to the inertia of the ,pendulous rod or the friction of the clamp I,

the rod will not move far enough to allow the pawl to pass over one of the teeth of the ratchet-wheel; but as the speed of the engine increases beyond the normal point the strokes of the arm H, connected with the piston or 2 5 valve rod, are faster and the striking force on the stops 9 greater, and thependulum is caused to move far enough to allow the pawl to engage one or more of the teeth of the ratchet, and to move the valve and reduce the pressure, and

this it does until the movements of the engine are normal. I

If the engine is running normally, and for any reason the work being donedecreases, the engine runs away, and as soon as it com- 5 mences to make more than the ordinary number of movements the striking force of the arm H increases and the pendulum is moved and continues to operate the valve 0 until the pressure is entirely removed.

0 'Other conditions mightbestated'specifically in which the safety device is automatically operated to reduce or extinguish the pressure upon the engine; but they are apparent to one skilled in the art.

;5 While the construction of the specific apparatus shown and described is well adapted to the kind of engine shown, it is evident that the construct-ion may be varied without departing from the principleoi my invention in such a manner as to adapt it for operation in connection with other forms of engines.

It is preferable, in using the arrangement shown in the drawings, to have the ratchetwheel screwed onto the valve-stem, thescrewthread being cut in such a direction that any movement of the ratchet-wheel by the pawl only tends to secure the wheel the tighter. Thus there can be no lost motion of the wheel, and it is not liable to become loose by use. A

handle or hand-wheel may be keyed on the 6 5 each reciprocation.

What I claim is- 1. In combination, a fluid-pressure engine,

its reciprocating piston, a valve to control the admission of fluid to said engine, avalveactuating device connected tosaid valve, means to hold said device and valve in normal stationary position, and means to cause said reciprocating piston to operate said device and its connected valve when it exceeds its normal speed andtravel, as and for the purpose specified. I

3. The combination, with the engine, its piston and supply-pipe, and a valve for controlling the fiow of fluid through said pipe, of a valve-actuating device and connections between the same and the piston, whereby said device is brought into operative connection with said valve only by the increased movement of said piston resulting from momentum due to the increase in speed thereof, substantially as described.

4. A fluid-pressure engine, its throttle-valve, and reciprocating piston, in combination with a device arranged in juxtaposition to said throttle-valve, means to throw said valveinto operative connection with said valve to close the same when the speed and travel of said piston exceeds its normal limits, and means to return said device to its normal position when the piston resumes its normal speed and travel,

substantially as described.

5. The combination,with a fluid-pressureengine, its supply-pipe, and a valve to control the passage of fluids through said pipe, of an actuating device connected to said valve, a rod pendent from said device, means to hold said rod in normal stationary position, and means to swing said rod and its attached valve-actuating device to close the valve when the engine speed and movement exceeds certain predetermined limits,substantially as described.

6. In a fluid-pressure engine,a cylinder,a reciprocating piston, a fluid-supply pipe, and a throttle valve to control the flow of fluid through said pipe, in combination with a valveaotuating device connected to said valve, a rod pendent from said device,elastic buffers to hold said rod in normal stationary position when the speed and movement of the engine are within certain predetermined limits, and means, substantially as described, to swing said pendent rod and its attached actuating device to close said throttle-valve when the speed and movement of the engine exceeds said limits, as and for the purpose specified.

7. The combination, with the engine and fluid-pressure pipe, of a valve in said pipe, a ratchet-wheel attached to said valve, a carrier attached to a moving part of the engine and provided with a pawlengaging said ratchet, and connections between said carrier and some moving part of the engine, substantially as described.

S. The combination, with the valve-stem having a ratchet attached thereto, of a swinging carrier pivoted on said valve-stem and provided with a pawl engaging the ratchet, a rod connected to the engine, and connections between said carrier and rod, substantially as de scribed.

9. The combination, in a safety attachment for engines, ofa valve-operating device,arecip rocating rod connected therewith to operate said device,a guide for said rod, atension device for said rod, and connections between said rod and a moving part of the engine,'substantia1ly as described.

10. The combination, in asafety attachment for engines, of a valve-operating device,a reciprocating rod connected to and operating said device, and provided with stops or collars arranged to be operated bya moving part of the engine, substantially as described. 2 5

11. The combination,with a valve-stem, of a ratchet screwed upon the stem,a pendulum-rod swinging upon the stem and carrying apawl, an adjustable weight upon the rod,and connections between the rod and the moving part of 0 the engine, substantially as described.

12. The combination,in a safety device for engines, of avalve-operating mechanism and connections between said mechanism and moving parts of the engine, the arrangement being such that under normal action the safety device will not be moved,while an abnormal operationwill operate the safety device to reduce the speed or stop the engine, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

Witnesses:

W. O. DUVALL, WM. A. HARRIES. 

